In a large plastic food storage bag, mix together 2 tablespoons ginger jam, the soy sauce, and the rice vinegar. Add the ribs, and toss to coat. Marinate in the fridge overnight.

Preheat the oven to 350°F. Spread the ribs on a foil-lined baking sheet, and boil the marinade. Pour the marinade over the ribs, and cover tightly with foil. Bake 1 hour and 45 minutes, then take the foil off the baking sheet, turn the ribs over and bake uncovered for 30 minutes. Heat the remaining 2 tablespoons ginger jam in a large saucepot over medium heat until it loosens in texture. Toss the ribs in the hot jam to coat. Scatter the chopped scallion over the ribs, and serve.